Method of making joints



Aug. 12 1924. 1,504,464

. H. A. DOUGLAS METHOD OFMAKING JOINTS Filed Jan. 27. 1921 s sheets-sheet 1 A. DQUGLAS METHOD OF MAKXNG JOINTS Filed Jan. 27. 1921 3 Sheets-Sheet 2 1,504,464 A. DOUGLA$ METHOD OF MAKING JOINTS Filed Jan. 27. 1921 3 Sheets-Sheet s Patented Aug. 12, 1924. V

UNITED STATES HARRY A. DOUGLAS, 01E BRQNSON, MICHIGAN.

METHOD OF MAKING- JOINTS.

Application filed January 27, 1921.

To all whom it may concern:

Be it known that I, HARRY A. DOUGLAS, citizen of the United States, residing at Bronson, in the county of Branch and State of Michigan, have invented a certain new and useful Improvement in Methods of Making Joint-s, of which the following is a full, clear, concise, and exact description.

. My invention relates to method of and machine for uniting edge portions of sheet material by mortises and tenons and is of particular utility when employed in forming a plurality of hollow bodies out of a sheet of suitable material such as brass. My invention has been employed for forming metallic shells which are used in the construction of circuit connectors or sockets but Tenons which con-form in configurationito these mortises and which are tobe fitted thereln are placed in registry with the de pressed material where-after these tenons are forced into the mortise spaces to: remove the depressed material to complete the formation of the mortises and effect the location of the tenons therein.

The method of my invention is of particular service in forming a plurality of hollow bodies out of a sheet of suitable material and the machine for practicing the preferred method of my invention itself preferably includes male and female dies. between which the sheet may be passed and cooperating to depress areas of the sheet that conform to rows of mortises, alternated with tenons, that are to be produced, a mandrel about which the sheet may be bent to bring previously completed tenons between the mandrel and sheet and into registry with the incomplete mortises, a female die opposite the mandrel and positioned to be in registry with the aforesaid completed tenons and partially completed mortises, and means for forcing movement of this latter die toward the mandrel and against portions of the sheet material that margin the aforesaid depressed portions thereof whereby said completed tenons complete the removal of Serial No. 440,483.

the depressed material and are entered within the resulting mortises, the latter die severing the tenons formed because of these mortises from the part of the sheet that is bent about the mandrel.

I will explain my invention more fully by reference to the accompanying drawings in which Fig. 1 is an end view of one form of machine that may be employed; Fig. 2 is a view of a part of the mechanism shown in Fig. 1 taken from the other side; Fig. 3 is a plan view, with parts broken away, of the machine shown in Figs. 1 and 2; Fig. 4 is an end view, partially in section, of a portion of the mechanism with the dies thereof adjusted preparatory to operating upon the sheet metal; Fig. 5 illustrates the parts shown in Fig. 4 after the dies have operated; Fig. 6 isa perspective view of the female die that finally operates to complete the formation of the hollow body or shell; Fig. 7 is a perspective view illustrating the female die and partially illustrating the male die in separated relation; Fig. 8 is a view on line 8'8 of Fig; 1; Fig. 9 is a view on line 9-9 of Fig. 5; Fig. 1,0 is a perspective View illustrating the sheet curled about the mandrel and before the dies have been brought into operation; Fig.11 is view similar to Fig. 10 and showing the sheet after the dies have been brought into operation; and Fig. 12 is a perspective view of one form of product of the method and the machine.

Like parts are indicated by similar char acters of reference throughout the different.

figures.

The female die 1 is normally held in fixed relation with the bed 2 by means of screws 3. A cap plate 4 is mounted upon the bed, there being spacing between this cap plate and bed for the passage of the sheet 5 of metal or other suitable material and for the reception of the, mandrel 6 about which the sheet is curled preparatory to the final die operation and the ejection of the product. The male die 7 is in registry with the female die 1, these dies being formed with complemental -T-shaped or other suitable dovetailed projections 8 and recesses 9. The male dies are forced into the female dies to an extent which will almost break down the areas of metal that conform to the mortises, the depressed metal indicated at 10 being therefore easily removed by the application of suflicient pressure exerted thereon through the intermediation of tenons, previously completed at the mandrel aswill later appear. Tenons are partially formed because ofthe mortises, as indicated at 11. After the mortises and tenons have thus been partially formed by the co-operation of the dies 1 and 7, as indicated at 10, 11, the sheet is advanced toward and curled about the mandrel to bring the partially completed mortises, indicated at 10, in registry with previously completed tenons 11 that .are disposed between the depressions and the mandrel. These completed tenons 11 and the partially completed mortises at 10, in addition to being in registery with each other, are also in registry with the female die 12 that is opposite the mandrel and "aligned with a radius thereof,there being means for forcing the die 12 toward the mandrel and against portions of the sheet material that margin the aforesaid depressed portions 11 whereby these marginingportions are forced against the mandrel and the completed tenons underlying the depressed portions to force such portions outwardly to complete the formation of the mortises that are to receive said completed tenons and to complete afresh set of tenons (Fig. 11) to be employed in a similar manner in theformation of a succeeding shell. The die 12, obviously, severs the tenons 11 last to be completed from the part of the sheet that is bent about the mandrel, these the new set of tenons as is understood from newly formed tenons 11 in turn occupying the position of the previous set of completed tenons that are employed in forming the previous description. The completed shell (Fig. 12) is ejected from the mandrel following the formation of a new set of tenons.

By means of the machine and method of my invention, trimming dies do not need to v be employed to remove the improperly slop- -ing edges of the mortises and tenons that for operating the various dies, which have been described, in orderly sequence and also for timely feeding the sheet material between the dies and about the mandrel, suitable mechamsm being shown in Figs. 1, 2

and 3. The dies 7 may be direct'iy mounted upon a reciprocatingcarrier 13 that may be vertically reciprocated by the powerful eccentric lconnected with the carrier 13.

The die 12 may be mounted to reciprocate in an oblique direction and in radial alignment with the mandrel. This die is provided with a stem 15 formed with a shoulder 16. A heavy spring 17 serves to remove the die out of the path of the sheet 5 when this sheetis to be curled about the mandrel. hen the die 7 is depressed to perform its function the cam 18, also mounted upon the carrier 13, engages the shoulder portion 16 of the stem 15 to press the die 12 inwardly tocause it to perform its function. After the carrier 13 is withdrawn to remove the die 7 from the plane of the sheet 5 and to permit the spring 17 to remove the die 12 from the path followed by this sheet in being curled about the mandrel, the pitman 19 is operated by the crank 19 and operates a crank 20, free of connection at its mounted end, that carries a pawl 21 that turns a ratchet wheel 22 a quarter of a revolution each time the pitman 19 is moved downwardly. This ratchet wheel is in fixed relation with the friction feeding disc 23 against which the sheet 5 is pressed by a friction idler wheel 26% that in turn is pressed upon by springs 25. One quarter of the circumferenceof the feeding disc 23 corresponds to the length of the sheet 5 that is required to form the shell. The extent to .which the disc is turned is limited by a stop 26 that engages the loosely mounted crank to hold this crank stationary and to prevent further feeding operation during any further downward movement of the crank 19, there being a spring 27 between sections of the pitman 19 that permits the upper pitman section to approach the lower pitman section when the latter is held from movement. A pawl 28 operates upon a star wheel 29 fixed with respect to the cam 29, this cam 29 operating upon a bell crank lever 30 to cause this lever to move an ejector sleeve 31 against each finished shell to discharge this shell from the mandrel, this operation occurring when the die 12 has performed its function and is withdrawn.

Claims upon the machine herein disclosed form the subject matter of my co-pending application Serial No. 67 8,209, filed Dec. 3, 1928, a division of this application.

lVhile I have herein shown and particularly described the preferred embodiment of my invention I do not wish to be limited to the precise details of constructionv shown as changes may readily be made without departing from the spirit of my invention,

but having thus described my invention I claim as new and desire to secure by Letters Patent the following:

1. The method of forming hollow bodies of sheet material which consists in forming a row of alternated mortises and tenons in. a sheet of the material out of which the hollow body is to be made; partially form-. ing a second row of alternated mortises and tenons by depressing material from the sheet in areas that are similar in arrangement and dimensions to the tenons in the first row; bending the sheet and bringing the tenons in the first row in registry with the partially formed mortises in the second row; and forcing the tenon portions in each IOW into the mortise spaces of the other row to remove the depressed material to complete the formation of the mortises and tenons in the second row and effect the location of the tenons in the mortises.

2. The method of forming a plurality of hollow bodies out of a sheet of suitable material Which consists in forming similar rows of partially completed alternated mortises and tenons by depressing the material from the sheet in areas that conform to the mortises that are to be produced; forming complete tenons; bending the sheet to place the completed tenons in registry With the partially formed mortises; forcing these completed tenons against the depressed ma te'rial to complete the removal thereof and effect the location of the completed tenons Within the mortises; and similarly employing the completed tenons remaining in the sheet, in the formation of another hollow body as herein set forth.

3. The method of uniting edge portions of sheet material by mortises and tenons Which consists in depressing the material that is to be removed to form a mortise; placing a tenon that conforms in configuration to such depressed material in registry With the depressed material; and forcing the tenon into the mortise space to remove the depressed material to complete the formation of the mortise and effect the location of the tenon Within the completed mortise.

In Witness whereof, I hereunto subscribe by name this 12th day of November A. D., 1920.

HARRY A. DOUGLAS. 

